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Ultrastructure of the somatic components of the testis of the Pacific hagfish was studied. Interstitial cells, equivalent to Leydig cells of higher vertebrates, containing smooth-surfaced endoplasmic reticulum and mitochondria with tubular cristae were found in the interstitial tissue, as well as leucocytes, fibroblasts and other cells of unknown role. Two kinds of somatic cells were observed in the testicular follicles: Sertoli cells and “stellate cells”. The significance of interstitial cells was discussed in relation to possible involvement in steroidogenesis. 相似文献
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Kei Watanabe Kenta Wada Tomoko Ohashi Saki Okubo Kensuke Takekuma Ryoichi Hashizume Jun-Ichi Hayashi Tadao Serikawa Takashi Kuramoto Yoshiaki Kikkawa 《PloS one》2012,7(11)
We discovered a new cataract mutation, kfrs4, in the Kyoto Fancy Rat Stock (KFRS) background. Within 1 month of birth, all kfrs4/kfrs4 homozygotes developed cataracts, with severe opacity in the nuclei of the lens. In contrast, no opacity was observed in the kfrs4/+ heterozygotes. We continued to observe these rats until they reached 1 year of age and found that cataractogenesis did not occur in kfrs4/+ rats. To define the histological defects in the lenses of kfrs4 rats, sections of the eyes of these rats were prepared. Although the lenses of kfrs4/kfrs4 homozygotes showed severely disorganised fibres and vacuolation, the lenses of kfrs4/+ heterozygotes appeared normal and similar to those of wild-type rats. We used positional cloning to identify the kfrs4 mutation. The mutation was mapped to an approximately 9.7-Mb region on chromosome 7, which contains the Mip gene. This gene is responsible for a dominant form of cataract in humans and mice. Sequence analysis of the mutant-derived Mip gene identified a 5-bp insertion. This insertion is predicted to inactivate the MIP protein, as it produces a frameshift that results in the synthesis of 6 novel amino acid residues and a truncated protein that lacks 136 amino acids in the C-terminal region, and no MIP immunoreactivity was observed in the lens fibre cells of kfrs4/kfrs4 homozygous rats using an antibody that recognises the C- and N-terminus of MIP. In addition, the kfrs4/+ heterozygotes showed reduced expression of Mip mRNA and MIP protein and the kfrs4/kfrs4 homozygotes showed no expression in the lens. These results indicate that the kfrs4 mutation conveys a loss-of-function, which leads to functional inactivation though the degradation of Mip mRNA by an mRNA decay mechanism. Therefore, the kfrs4 rat represents the first characterised rat model with a recessive mutation in the Mip gene. 相似文献
25.
To examine geographic differentiation in Asarum heterotropoides var. heterotropoides in Hokkaido Is. in the northern Japan, in which two putative cryptic species have been suspected to exist, extensive and
detailed morphological research on 794 individuals from 44 populations throughout Hokkaido Is. was performed. Among the characters
examined, the angle between and tip shape of the calyx lobes and the supratecta of the pollen grains were significantly correlated
and were found in similar geographic clines. Among them, the pollen showed two discrete states in almost distinct distribution.
Multidimensional scaling analysis showed that individuals within each of the two pollen types had different trends in flower
characters. Consequently, we assumed a cline from south to north on Hokkaido Is. For the causes of the cline, the two hypotheses
were proposed, primary geographic differentiation or extensive introgressive hybridization between two distinct geographical
species existing in the past. 相似文献
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Kiichiro Teruya Yoshihito Daimon Xiao-Yan Dong Yoshinori Katakura Takumi Miura Akira Ichikawa Tsukasa Fujiki Makiko Yamashita Tetsuya Mori Hideya Ohashi Sanetaka Shirahata 《Cytotechnology》2005,47(1-3):29-36
The cell line D29, which was easily and rapidly established by the promoter-activated production and glutamine synthetase
hybrid system, secreted recombinant human interleukin-6 (hIL-6) at a productivity rate of 39.5 μg 10−6 cells day−1, one of the highest reported levels worldwide. The productivity rate was about 130-fold higher than that of the cell line
A7, which was established without both promoter activation and gene amplification. Although D29 cells had a high copy number
and high mRNA level of the hIL-6 gene as well as a high secretion rate of hIL-6, large amounts of intracellular hIL-6 protein
accumulated in D29 cells compared to A7 cells. Northern blotting analysis showed no change in the GRP78/BiP expression level
in D29 cells. In contrast, an electrophoresis mobility shift assay revealed strong activation of NF-κB in D29 cells. These
results suggest that large amounts of hIL-6 translated from large amounts of hIL-6 mRNA cause excess accumulation of intact
hIL-6 in the endoplasmic reticulum (ER), and that subsequent negative feedback signals via the ER overload response inhibit
hIL-6 protein secretion. To enhance the hIL-6 productivity rate of D29 cells by releasing the negative feedback signals, the
effect of pyrrolidinedithiocarbamate, an inhibitor of NF-κB activation, was examined. Suppression of NF-κB activation in D29
cells produced a 25% augmentation of the hIL-6 productivity rate. Therefore, in highly productive cells like D29 cells, the
release of negative feedback signals could increase the total amount of recombinant protein secretion. 相似文献
28.
Ciborinia gentianae sp. nov., the causal organism of sclerotial flower blight of cut-flower gentians
A new Ciborinia causing sclerotial flower blight of cut-flower gentians (Gentiana triflora var. japonica and interspecific hybrids between related species or varieties) is described as Ciborinia gentianae on the morphological basis of sclerotia and apothecia. The characteristics of Ciborinia gentianae are (1) an abundant production of spermodochia in the hollow cavity of host stems; (2) flat and thin sclerotia produced beneath
the epidermis and the inclusion of host vascular remnants within their medulla; (3) globose cells composed of ectal excipulum
of apothecia; (4) elongated cells with a slight apical swelling in ectal excipulum at the apothecial margin; and (5) tetra
nucleate ascospores. Asci and ascospores mounted in Melzer's reagent measured 156–208 × 8–12 μm and 11.8–15 × 5.5–7.1 μm,
respectively. 相似文献
29.
Yufeng Li Yusuke Miyanari Kenjiro Shirane Hirohisa Nitta Takeo Kubota Hirofumi Ohashi Akimitsu Okamoto Hiroyuki Sasaki 《Nucleic acids research》2013,41(19):e186
Methylation-specific fluorescence in situ hybridization (MeFISH) was developed for microscopic visualization of DNA methylation status at specific repeat sequences in individual cells. MeFISH is based on the differential reactivity of 5-methylcytosine and cytosine in target DNA for interstrand complex formation with osmium and bipyridine-containing nucleic acids (ICON). Cell nuclei and chromosomes hybridized with fluorescence-labeled ICON probes for mouse major and minor satellite repeats were treated with osmium for crosslinking. After denaturation, fluorescent signals were retained specifically at satellite repeats in wild-type, but not in DNA methyltransferase triple-knockout (negative control) mouse embryonic stem cells. Moreover, using MeFISH, we successfully detected hypomethylated satellite repeats in cells from patients with immunodeficiency, centromeric instability and facial anomalies syndrome and 5-hydroxymethylated satellite repeats in male germ cells, the latter of which had been considered to be unmethylated based on anti-5-methylcytosine antibody staining. MeFISH will be suitable for a wide range of applications in epigenetics research and medical diagnosis. 相似文献
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